Vegetarian Science
T. Colin Campbell's book The China Study was published in 2006. It made a
science-based case for a whole-food plant-based diet. To determine the currency of his
arguments, a search of Pubmed articles that included the key word "vegetarian" was
carried out for the period 2007 to March 2013. A review of the abstracts generated by this
search was carried out to select articles that compared "vegetarian" diets to other
diets, or addressed the health and safety of "vegetarian" diets. Summaries of the
former articles are provided below, and these summaries include links to the original articles.
The key observation from the review is a substantiation of Campbell's arguments as
presented in 2006. The benefits of a "vegetarian" diet include reduced risks of
cancer, heart disease, stroke, diabetes, cataracts, diverticular disease rheumatoid arthritis
and organo-chlorines.
Note however that Campbell recommended a particular type of vegetarian diet, namely
a whole food, plant-based diet. Campbell's recommended diet excludes most processed plant-based foods, eggs,
dairy, and recommends only a limited amount of fish. Potentially, Campbell's recommended diet could produce better
results than those captured in the recent scientific studies of vegetarian diets.
The downside issues with a "vegetarian" diet (Vitamin B12
deficiency, Vitamin D deficiency, renal functions, osteoporosis) have been much studied, with
the general conclusion that well-planned "vegetarian" diet is safe and healthy. A summary
of these abstracts is provided separately. To see these abstracts, click
here.
Over the time, the articles appear to focus less on the health and safety of
"vegetarian" diets, and increasingly on the different kinds of "Vegetarian"
diet (i.e. vegan; vegetarian plus eggs; vegetarian plus dairy; vegetarian plus fish; vegetarian
with some combination of eggs, dairy and fish). In addition, the studies are becoming
increasing more reliable as sample sizes increase.
Study Results
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Vegetarianism as a Protective Factor
for Reflux Esophagitis: A Retrospective, Cross-Sectional Study Between Buddhist Priests and
General Population by Jung JG,Kang HW,Hahn SJ,Kim JH,Lee JK,Lim YJ,Koh MS,Lee JH in
Dig Dis Sci.2013 Mar 19. "The aim of this study is to elucidate the protective
effect of vegetarianism for reflux esophagitis...This is a cross-sectional study
that compared the prevalence of reflux esophagitis of 148 Buddhist priests, who are
obligatory vegetarians with that of age- and sex-matched controls who underwent health
checkups in a health promotion center...A non-vegetarian diet is associated with reflux
esophagitis."
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Risk of hospitalization or death from
ischemic heart disease among British vegetarians and nonvegetarians: results from the
EPIC-Oxford cohort study by Crowe FL, Appleby PN, Travis RC, Key TJ. in Am J Clin
Nutr. 2013 Mar;97(3):597-603 "The objective was to examine the association of a
vegetarian diet with risk of incident (nonfatal and fatal) Ischemic Heart Disease
(IHD)...Vegetarians had a 32% lower risk ... of IHD than did nonvegetarians, which was only
slightly attenuated after adjustment for BMI and did not differ materially by sex, age,
BMI, smoking, or the presence of IHD risk factors. Consuming a vegetarian diet was
associated with lower IHD risk, a finding that is probably mediated by differences in
non-HDL cholesterol, and systolic blood pressure."
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Systematic review and meta-analysis
of different dietary approaches to the management of type 2 diabetes by Ajala O,
English P, Pinkney J. in Am J Clin Nutr. 2013 Mar;97(3):505-16 "We assessed the
effect of various diets on glycemic control, lipids, and weight loss...We included
randomized controlled trials (RCT) with interventions that lasted =6 mo that compared
low-carbohydrate, vegetarian, vegan, low-glycemic index (GI), high-fiber, Mediterranean,
and high-protein diets with control diets including low-fat, high-GI, American Diabetes
Association, European Association for the Study of Diabetes, and low-protein
diets...The low-carbohydrate, low-GI, Mediterranean, and high-protein diets all led to a
greater improvement in glycemic control...compared with their respective control diets,
with the largest effect size seen in the Mediterranean diet. Low-carbohydrate and
Mediterranean diets led to greater weight loss...with an increase in HDL seen in all diets
except the high-protein diet."
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The effect of lifestyle food on
chronic diseases: a comparison between vegetarians and non-vegetarians in Jordan by
Alrabadi NI in Glob J Health Sci. 2012 Nov 4;5(1):65-9. "This cross sectional
study...compared these (chronic) diseases between vegetarians and non- vegetarians in
Jordan in 2012...(C)hronic diseases including Diabetes, Hypertension, and
Obesity were more prevalence among non-vegetarians compared to vegetarian
respondents."
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Vegetarian diets and the incidence of
cancer in a low-risk population by Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser
G in Cancer Epidemiol Biomarkers Prev. 2013 Feb;22(2):286-94. "...We examined
the association between dietary patterns (non-vegetarians, lacto, pesco, vegan, and
semi-vegetarian) and the overall cancer incidence among 69,120 participants of the
Adventist Health Study-2...Vegetarian diets seem to confer protection against cancer...
Vegan diet seems to confer lower risk for overall and female-specific cancer than other
dietary patterns. The lacto-ovo-vegetarian diets seem to confer protection from cancers of
the gastrointestinal tract.
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Vegetarian diets, low-meat diets and
health: a review by McEvoy CT, Temple N, Woodside JV in Public Health Nutr. 2012
Dec;15(12):2287-94. "...Both vegetarian diets and prudent diets allowing small
amounts of red meat are associated with reduced risk of diseases, particularly CHD
and type 2 diabetes. There is limited evidence of an association between vegetarian
diets and cancer prevention. Evidence linking red meat intake, particularly
processed meat, and increased risk of CHD, cancer and type 2 diabetes is convincing and
provides indirect support for consumption of a plant-based diet...At this time an optimal
dietary intake for health status is unknown. Plant-based diets contain a host of food and
nutrients known to have independent health benefits."
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Cardiovascular disease mortality and
cancer incidence in vegetarians: a meta-analysis and systematic review by Huang T, Yang
B, Zheng J, Li G, Wahlqvist ML, Li D in Ann Nutr Metab. 2012;60(4):233-40.
"...The objective of the ... meta-analysis was to investigate cardiovascular
disease mortality and cancer incidence among vegetarians and
nonvegetarians...Our results suggest that vegetarians have a significantly lower ischemic
heart disease mortality (29%) and overall cancer incidence (18%) than nonvegetarians."
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Long-term vegetarians have low
oxidative stress, body fat, and cholesterol levels by Kim MK, Cho SW, Park YK in
Nutr Res Pract. 2012 Apr;6(2):155-61. "...We compared biomarkers of
oxidative stress, antioxidant capacity, and lipid profiles of sex- and
age-matched long-term vegetarians and omnivores in Korea...(O)xidative stress, body fat,
and cholesterol levels were lower in long-term vegetarians than those in omnivores."
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Chinese lacto-vegetarian diet exerts
favorable effects on metabolic parameters, intima-media thickness, and cardiovascular risks
in healthy men by Yang SY, Li XJ, Zhang W, Liu CQ, Zhang HJ, Lin JR, Yan B, Yu YX, Shi
XL, Li CD, Li WH in Nutr Clin Pract. 2012 Jun;27(3):392-8. "...To investigate
whether the Chinese lacto-vegetarian diet has protective effects on metabolic and
cardiovascular disease (CVD)...Compared with omnivores, lacto-vegetarians had
remarkably lower body mass index, systolic and diastolic blood pressure, and serum levels
of triglyceride, total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B,
?-glutamyl transferase, serum creatinine, uric acid, fasting blood glucose, as well as
lower total cholesterol/high-density lipoprotein cholesterol ratio. Vegetarians also had
higher homeostasis model assessment ? cell function and insulin secretion index and thinner
carotid IMT than the omnivores did. These results corresponded with lower cardiovascular
risk points and probability of developing CVD in 5-10 years in vegetarians 24-55 years
old."
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Restriction of meat, fish, and
poultry in omnivores improves mood: a pilot randomized controlled trial by Beezhold BL,
Johnston CS in Nutr J. 2012 Feb 14;11:9. "...This study investigated the impact
of restricting meat, fish, and poultry on mood...Restricting meat, fish, and poultry
improved some domains of short-term mood state in modern omnivores."
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Vegetarian diets and blood pressure
among white subjects: results from the Adventist Health Study-2 (AHS-2) by Pettersen
BJ, Anousheh R, Fan J, Jaceldo-Siegl K, Fraser GE in Public Health Nutr. 2012
Oct;15(10):1909-16. "...(T)he vegan vegetarians had lower systolic and diastolic
BP (mmHg) than omnivorous Adventists... Findings for lacto-ovo vegetarians ... were
similar...We conclude from this relatively large study that vegetarians, especially vegans,
with otherwise diverse characteristics but stable diets, do have lower systolic and
diastolic BP and less hypertension than omnivores. This is only partly due to their
lower body mass.
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Selected biomarkers of age-related
diseases in older subjects with different nutrition by Krajcovicova-Kudlackova M,
Babinska K, Blazicek P, Valachovicova M, Spustova V, Mislanova C, Paukova V. in Bratisl
Lek Listy. 2011;112(11):610-3. "...Markers of age-related diseases
(cardiovascular, metabolic syndrome, diabetes) were assessed in two
nutritional groups ... vegetarians (lacto-ovo-vegetarians and semi-vegetarians) and ...
non-vegetarians...Vegetarian values of total cholesterol, LDL-cholesterol,
triacylglycerols, C-reactive protein, glucose, insulin and insulin resistance are
significantly reduced. Non-vegetarian average values of total cholesterol, LDL-cholesterol
and C-reactive protein are risk. Vegetarians have a better antioxidative status
(significantly increased vitamin C, lipid-standardized vitamine E and beta-carotene plasma
concentrations)"
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Relation between dietary and
circulating lipids in lacto-ovo vegetarians by Fernandes Dourado K, de Arruda C?mara E
Siqueira Campos F, Sakugava Shinohara NK in Nutr Hosp. 2011 Sep-Oct;26(5):959-64.
"The aim of the present study was to compare diet, lipid profile and blood
pressure levels in Brazilian lacto-ovo vegetarians and non-vegetarians...No differences
were found regarding nutritional status based on the BMI...Regarding blood pressure, the
only difference between groups was systolic arterial pressure, which was higher among the
non-vegetarians...Mean total cholesterol and LDL were higher among non-vegetarians. Mean
serum TG (triglyceride) was higher among the vegetarians. The greater consumption of
carbohydrates among the vegetarians was reflected in the higher serum triglyceride levels.
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Vegetarian diets and incidence of
diabetes in the Adventist Health Study-2 by Tonstad S, Stewart K, Oda K, Batech M,
Herring RP, Fraser GE in Nutr Metab Cardiovasc Dis. 2013 Apr;23(4):292-9. "To
evaluate the relationship of diet to incident diabetes among non-Black and Black
participants in the Adventist Health Study-2...Participants were grouped as vegan, lacto
ovo vegetarian, pesco vegetarian, semi-vegetarian or non-vegetarian (reference
group)...Vegetarian diets (vegan, lacto ovo, semi-) were associated with a substantial and
independent reduction in diabetes incidence. In Blacks the dimension of the protection
associated with vegetarian diets was as great as the excess risk associated with Black
ethnicity."
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Veganism does not reduce the risk of
the metabolic syndrome in a Taiwanese cohort by Shang P, Shu Z, Wang Y, Li N, Du S, Sun
F, Xia Y, Zhan S in Asia Pac J Clin Nutr. 2011;20(3):404-10. "The purpose of
the present study was to assess the risk of the metabolic syndrome (MS) with vegan,
pescovegetarian, lactovegetarian and nonvegetarian diets in Taiwan...Our data suggest that
the vegan diets did not decrease the risk of metabolic syndrome compared with
pescovegetarian, lactovegetarian and nonvegetarian diets in a Taiwanese cohort."
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Diet and risk of diverticular disease
in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC):
prospective study of British vegetarians and non-vegetarians by Crowe FL, Appleby PN,
Allen NE, Key TJ in BMJ. 2011 Jul 19;343:d4131. "...To examine the associations
of a vegetarian diet and dietary fibre intake with risk of diverticular
disease...Consuming a vegetarian diet and a high intake of dietary fibre were both
associated with a lower risk of admission to hospital or death from diverticular disease.
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A vegetarian dietary pattern as a
nutrient-dense approach to weight management: an analysis of the national health and
nutrition examination survey 1999-2004 by Farmer B, Larson BT, Fulgoni VL 3rd,
Rainville AJ, Liepa GU in J Am Diet Assoc. 2011 Jun;111(6):819-27. "...To
compare dietary quality of vegetarians, nonvegetarians, and dieters, and to test the
hypothesis that a vegetarian diet would not compromise nutrient intake when used to manage
body weight...Mean intakes of fiber, vitamins A, C, and E, thiamin, riboflavin, folate,
calcium, magnesium, and iron were higher for all vegetarians than for all nonvegetarians.
Although vegetarian intakes of vitamin E, vitamin A, and magnesium exceeded that of
nonvegetarians ..., both groups had intakes that were less than desired. ...These findings
suggest that vegetarian diets are nutrient dense, consistent with dietary guidelines, and
could be recommended for weight management without compromising diet quality.
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Nutritional status, lifestyle and
cardiovascular risk in lacto-ovo vegetarians and omnivore] by Fernandes Dourado K,
Campos Fde A, Rojas HF, Simi?es SK, de Siqueira LP in Arch Latinoam Nutr. 2010
Sep;60(3):220-6. "The aim of the present study was to assess socioeconomic
characteristics, dietary intake, nutritional status and cardiovascular risk (using
anthropometric indicators of central obesity) in lacto-ovo vegetarians and
non-vegetarians...The results of the present study suggest that, although a
lacto-ovovegetarian diet is considered healthier due to the lower consumption of total fat,
saturated fatty acids and cholesterol, there are no significant differences in nutritional
status or anthropometric indicators of cardiovascular risk when lifestyle and total calorie
intake are similar.
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Vegetarian diet improves insulin
resistance and oxidative stress markers more than conventional diet in subjects with Type 2
diabetes by Kahleova H, Matoulek M, Malinska H, Oliyarnik O, Kazdova L, Neskudla T,
Skoch A, Hajek M, Hill M, Kahle M, Pelikanova T. inDiabet Med. 2011
May;28(5):549-59. "The aim of this study was to compare the effects of
calorie-restricted vegetarian and conventional diabetic diets alone and in combination with
exercise on insulin resistance, visceral fat and oxidative stress markers in subjects with
Type 2 diabetes...Forty-three per cent of participants in the experimental group and
5% of participants in the control group reduced diabetes medication... Body weight
decreased more in the experimental group than in the control group...An increase in insulin
sensitivity was significantly greater in the experimental group than in the control
group...A reduction in both visceral and subcutaneous fat was greater in the experimental
group than in the control group...Differences between groups were greater after the
addition of exercise training. Changes in insulin sensitivity and enzymatic oxidative
stress markers correlated with changes in visceral fat...The greater loss of visceral fat
and improvements in plasma concentrations of adipokines and oxidative stress markers with
this diet may be responsible for the reduction of insulin resistance. The addition of
exercise training further augmented the improved outcomes with the vegetarian diet."
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Diet, vegetarianism, and cataract
risk by Appleby PN, Allen NE, Key TJ in Am J Clin Nutr. 2011 May;93(5):1128-35.
"We investigated the association between diet and cataract risk in a population
that has a wide range of diets and includes a high proportion of vegetarians...There was a
strong relation between cataract risk and diet group, with a progressive decrease in risk
of cataract in high meat eaters to low meat eaters, fish eaters (participants who ate fish
but not meat), vegetarians, and vegans...Vegetarians were at lower risk of cataract than
were meat eaters in this cohort of health-conscious British residents."
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Vegetarian dietary patterns are
associated with a lower risk of metabolic syndrome: the adventist health study 2 by
Rizzo NS, Sabat? J, Jaceldo-Siegl K, Fraser GE in Diabetes Care. 2011
May;34(5):1225-7. "The study objective was to compare dietary patterns in their
relationship with metabolic risk factors (MRFs) and the metabolic syndrome
(MetS)...A vegetarian dietary pattern was associated with significantly lower means for all
MRFs except HDL ...and a lower risk of having MetS ... when compared with a nonvegetarian
dietary pattern...A vegetarian dietary pattern is associated with a more favorable profile
of MRFs and a lower risk of MetS. The relationship persists after adjusting for lifestyle
and demographic factors."
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Nutrition concerns and health effects
of vegetarian diets by Craig WJ in Nutr Clin Pract. 2010 Dec;25(6):613-20.
"...When a vegetarian diet is appropriately planned and includes fortified foods, it
can be nutritionally adequate for adults and children and can promote health and lower the
risk of major chronic diseases. The nutrients of concern in the diet of vegetarians include
vitamin B(12), vitamin D, Omega-3 fatty acids, calcium, iron, and zinc...(V)egetarians
typically have lower body mass index, serum total and low-density lipoprotein cholesterol
levels, and blood pressure; reduced rates of death from ischemic heart disease; and
decreased incidence of hypertension, stroke, type 2 diabetes, and certain cancers than do
nonvegetarians."
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Comparison of renal function and
other health outcomes in vegetarians versus omnivores in Taiwan by Lin CK, Lin DJ, Yen
CH, Chen SC, Chen CC, Wang TY, Chou MC, Chang HR, Lee MC in J Health Popul Nutr. 2010
Oct;28(5):470-5. "...The study explored the effects of both the diets (diet of
plant origin, and diet of plant and animal origin) on renal functions. The study
subjects included 102 Buddhist nun vegetarians and an equal number of matched control group
(omnivores)...There was no difference in the renal functions between the two groups.
However, systolic blood pressure, blood urea nitrogen, serum sodium, glucose, cholesterol
levels, and urinary specific gravity were lower in the vegetarian group."
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Plasma concentrations of
25-hydroxyvitamin D in meat eaters, fish eaters, vegetarians and vegans: results from the
EPIC-Oxford study by Crowe FL, Steur M, Allen NE, Appleby PN, Travis RC, Key TJ in
Public Health Nutr. 2011 Feb;14(2):340-6. "Vegetarians and vegans exclude
certain food sources of vitamin D from their diet, but it is not clear to what
extent this affects plasma concentrations of 25-hydroxyvitamin D (25(OH)D). The objective
was to investigate differences in vitamin D intake and plasma concentrations of 25(OH)D
among meat eaters, fish eaters, vegetarians and vegans...Plasma 25(OH)D concentrations were
lower in vegetarians and vegans than in meat and fish eaters; diet is an important
determinant of plasma 25(OH)D in this British population."
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Serum concentrations of vitamin B12
and folate in British male omnivores, vegetarians and vegans: results from a
cross-sectional analysis of the EPIC-Oxford cohort study by Gilsing AM, Crowe FL,
Lloyd-Wright Z, Sanders TA, Appleby PN, Allen NE, Key TJ in Eur J Clin Nutr. 2010
Sep;64(9):933-9. "...The objectives of this study were to investigate differences
in serum vitamin B12 and folate concentrations between omnivores, vegetarians
and vegans and to ascertain whether vitamin B12 concentrations differed by age and time on
the diet...In all, 52% of vegans, 7% of vegetarians and one omnivore were classified as
vitamin B12 deficient...There was no significant association between age or duration of
adherence to a vegetarian or a vegan diet and serum vitamin B12. In contrast, folate
concentrations were highest among vegans, intermediate among vegetarians and lowest among
omnivores, but only two men (both omnivores) were categorized as folate deficient ..."
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Relationship between major dietary
patterns and metabolic syndrome among individuals with impaired glucose tolerance by
Amini M, Esmaillzadeh A, Shafaeizadeh S, Behrooz J, Zare M in Nutrition. 2010
Oct;26(10):986-92 "...This study focused on the association between major dietary
patterns and prevalence of the metabolic syndrome in individuals with impaired
glucose tolerance...Five major dietary patterns were found: a western pattern (high in
sweets, butter, soda, mayonnaise, sugar, cookies, tail of a lamb, hydrogenated fat, and
eggs), a prudent pattern (high in fish, peas, honey, nuts, juice, dry fruits, vegetable
oil, liver and organic meat, and coconuts and low in hydrogenated fat and non-leafy
vegetables), a vegetarian pattern (high in potatoes, legumes, fruits rich in vitamin C,
rice, green leafy vegetables, and fruits rich in vitamin A), a high-fat dairy pattern (high
in high-fat yogurt and high-fat milk and low in low-fat yogurt, peas, and bread), and a
chicken and plant pattern (high in chicken, fruits rich in vitamin A, green leafy
vegetables, and mayonnaise and low in beef, liver, and organic meat). After adjusting for
confounding variables, the western pattern was associated with greater odds of having
increased triacylglycerol ... and blood pressure... The prudent pattern was positively
associated with a prevalence of low high-density lipoprotein cholesterol levels... The
vegetarian dietary pattern was inversely associated with a risk of an abnormal fasting
blood glucose level..."
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Nutritional status of Flemish
vegetarians compared with non-vegetarians: a matched samples study by Deriemaeker P,
Alewaeters K, Hebbelinck M, Lefevre J, Philippaerts R, Clarys P in Nutrients. 2010
Jul;2(7):770-80. "The present study compares the nutritional status of vegetarian
(V) with non-vegetarian (NV) subjects...Our results clearly indicate that a vegetarian diet
can be adequate to sustain the nutritional demands to at least the same degree as that of
omnivores. The intakes of the V subjects were closer to the recommendations for a healthy
diet when compared to a group of well matched NV subjects."
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Haematological, biochemical and bone
density parameters in vegetarians and non-vegetarians by Sambol SZ, Stimac D, Orlic ZC,
Guina T in West Indian Med J. 2009 Dec;58(6):512-7. "The objective is to
determine any possible differences between haematological, biochemical and bone mineral
density in vegetarians (vegans and lacto-ovovegetarians) and non-vegetarians...The
results showed that lacto-ovovegetarians had statistically significantly higher red blood
cell counts and haematocrit values than non-vegetarians. Vegans also had higher haematocrit
values than non-vegetarians. Statistically significant differences were found between iron
plasma levels in the examined groups. Iron levels were lower in non-vegetarians than in
vegans and lacto-ovovegetarians. Non-vegetarians had much higher levels of cholesterol,
triglycerides and LDL than the other two groups, but there were no differences found
between same values in vegans and lacto-ovovegetarians...A well planned and balanced
vegetarian diet, with avoidance of risk factors, does not result in abnormalities in
laboratory tests and bone status parameters."
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Vegetarian diets are associated with
healthy mood states: a cross-sectional study in seventh day adventist adults by
Beezhold BL, Johnston CS, Daigle DR in Nutr J. 2010 Jun 1;9:26. "...We examined
associations between mood state and polyunsaturated fatty acid intake as a result of
adherence to a vegetarian or omnivorous diet...Vegetarians ... reported significantly less
negative emotion than omnivores... VEG reported significantly lower mean intakes of EPA
..., as well as the omega-6 fatty acid, arachidonic acid ..., and reported higher mean
intakes of shorter-chain alpha-linolenic acid ... and linoleic acid...(P)articipants with
low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood...The
vegetarian diet profile does not appear to adversely affect mood despite low intake of
long-chain omega-3 fatty acids."
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Vegetarian diets and childhood
obesity prevention by Sabat? J, Wien M in Am J Clin Nutr. 2010
May;91(5):1525S-1529S. "...The focus of this article is to review the relation
between vegetarian diets and obesity, particularly as they relate to childhood
obesity. Epidemiologic studies indicate that vegetarian diets are associated with a lower
body mass index (BMI) and a lower prevalence of obesity in adults and children. A
meta-analysis of adult vegetarian diet studies estimated a reduced weight difference of 7.6
kg for men and 3.3 kg for women, which resulted in a 2-point lower BMI... Similarly,
compared with nonvegetarians, vegetarian children are leaner, and their BMI difference
becomes greater during adolescence..."
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Nutrient based estimation of
acid-base balance in vegetarians and non-vegetarians by Deriemaeker P, Aerenhouts D,
Hebbelinck M, Clarys P in Plant Foods Hum Nutr. 2010 Mar;65(1):77-82. "... The
findings of this study indicate that vegetarian food intake produces more alkaline
outcomes compared to non-vegetarian diets. The use of the standard PRAL table was
sufficient for discrimination between the two diets."
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Impact of adopting a vegan diet or an
olestra supplementation on plasma organochlorine concentrations: results from two pilot
studies by Arguin H, S?nchez M, Bray GA, Lovejoy JC, Peters JC, Jandacek RJ, Chaput JP,
Tremblay A in Br J Nutr. 2010 May;103(10):1433-41. "...The aim of these studies
was to evaluate the potential of some nutritional approaches to prevent or reduce the body
load of organochlorines (OC) in humans. Study 1 compared plasma OC concentrations
between vegans and omnivores while study 2 verified if the dietary fat substitute olestra
could prevent the increase in OC concentrations that is generally observed in response to a
weight-reducing programme...In study 1, plasma concentrations of five OC compounds (aroclor
1260 and PCB 99, PCB 138, PCB 153 and PCB 180) were significantly lower in vegans compared
with omnivores. In study 2, beta-HCH was the only OC which decreased in the fat-substituted
group while increasing in the other two groups... In conclusion, there was a trend toward
lesser contamination in vegans than in omnivores, and olestra had a favourable influence on
beta-HCH but did not prevent plasma hyperconcentration of the other OC during ongoing
weight loss.
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Dietary patterns and adult asthma:
population-based case-control study by Bakolis I, Hooper R, Thompson RL, Shaheen SO in
Allergy. 2010 May;65(5):606-15. "...We carried out a population-based
case-control study of asthma in adults aged between 16 and 50 in South London,
UK.... A 'prudent' dietary pattern (wholemeal bread, fish and vegetables) was
positively associated with chronic bronchitis ... Overall there were no clear relations
between dietary patterns and adult asthma..."
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Enhanced bone metabolism in
vegetarians--the role of vitamin B12 deficiency by Herrmann W, Obeid R, Schorr H,
H?bner U, Geisel J, Sand-Hill M, Ali N, Herrmann M in Clin Chem Lab Med.
2009;47(11):1381-7. "...Vitamin B12 deficiency and bone fractures
are common in vegetarians. However, a direct relationship between vitamin B12 status and
bone metabolism in vegetarians has not been tested sufficiently...Low vitamin B12 status is
related to increased bone turnover in vegetarians which is independent from vitamin D
status."
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Effects of plant-based diets on
plasma lipids by Ferdowsian HR, Barnard ND in Am J Cardiol. 2009 Oct
1;104(7):947-56. "...The investigators ...reviewed the published scientific
research to determine the effectiveness of plant-based diets in modifying plasma lipid
concentrations...Of the 4 types of plant-based diets considered, interventions testing
a combination diet (a vegetarian or vegan diet combined with nuts, soy, and/or fiber)
demonstrated the greatest effects ..., followed by vegan and ovolactovegetarian diets.
Interventions allowing small amounts of lean meat demonstrated less dramatic reductions in
total cholesterol and low-density lipoprotein levels."
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The association between high plasma
homocysteine levels and lower bone mineral density in Slovak women: the impact of
vegetarian diet by Krivosikova Z, Krajcovicova-Kudlickova M, Spustova V, Stefikova K,
Valachovicova M, Blazicek P, Nemcova T in Eur J Nutr. 2010 Apr;49(3):147-53.
"...To assess the possible impact of a vegetarian diet on bone mineral density
in cohort of Slovak vegetarian women...Vegetarians had a significantly lower weight ...,
and homocysteine...Vitamin B(12) was significantly higher in nonvegetarians... No
differences were observed in folate levels...Homocysteine is one of the predictors of bone
mineral density...In healthy adults, homocysteine levels are dependent on age as well as on
nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of
osteoporosis development than nonvegetarian women."
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Relationship between animal protein
intake and muscle mass index in healthy women by Aubertin-Leheudre M, Adlercreutz Hi in
Br J Nutr. 2009 Dec;102(12):1803-10. "...The aim was to examine the
relationship between the type of protein intake and the level of muscle mass in
healthy omnivorous and vegetarian Caucasian women...(A) vegetarian diet is associated with
a lower muscle mass index than is an omnivorous diet at the same protein intake...."
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Effect of vegetarian diets on bone
mineral density: a Bayesian meta-analysis by Ho-Pham LT, Nguyen ND, Nguyen TV in Am
J Clin Nutr. 2009 Oct;90(4):943-50. "...The aim of this study was to estimate the
effect of vegetarian diets on BMD (bone mineral density) by using a meta-analytic
approach...The results suggest that vegetarian diets, particularly vegan diets, are
associated with lower BMD, but the magnitude of the association is clinically
insignificant."
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Cancer incidence in British
vegetarians by Key TJ, Appleby PN, Spencer EA, Travis RC, Allen NE, Thorogood M, Mann
JI in Br J Cancer. 2009 Jul 7;101(1):192-7. "...We studied 61,566 British men
and women, comprising 32,403 meat eaters, 8562 non-meat eaters who did eat fish ('fish
eaters') and 20,601 vegetarians. After an average follow-up of 12.2 years, there were
3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters
and 829 among vegetarians...The incidence of some cancers may be lower in fish eaters and
vegetarians than in meat eaters."
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DHA status of vegetarians by
Sanders TA in Prostaglandins Leukot Essent Fatty Acids 2009 Aug-Sep;81(2-3):137-41.
"...To review DHA status in vegetarians and vegans...Dietary analyses show that
vegan diets are devoid of DHA and vegetarian diets that included dairy food and eggs only
provide about 0.02 g DHA/d. Vegetarian and especially vegan diets supply more linoleic acid
... than omnivore diets. The intake of alpha-linolenic acid ... also tends to be similar or
greater but depends on culinary oils used. The proportions of DHA in plasma, blood cells,
breast milk, and tissues are substantially lower in vegans and vegetarians compared with
omnivores. The lower proportions of DHA are accompanied by correspondingly higher
proportions of the long-chain derivatives of linoleic acid, indicating that the capacity to
synthesize long-chain polyunsaturated fatty acids is not limited. Short-term dietary
supplementation with alpha-linolenic acid ... does not increase the proportion of DHA in
blood lipids...There is no evidence of adverse effects on health or cognitive function with
lower DHA intake in vegetarians..."
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Vegetarian and vegan diets in type 2
diabetes management by Barnard ND, Katcher HI, Jenkins DJ, Cohen J, Turner-McGrievy G
in Nutr Rev. 2009 May;67(5):255-63. "...The presently available literature
indicates that vegetarian and vegan diets present potential advantages for the management
of type 2 diabetes."
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Type of vegetarian diet, body weight,
and prevalence of type 2 diabetes by Tonstad S, Butler T, Yan R, Fraser GE in
Diabetes Care. 2009 May;32(5):791-6. "...We assessed the prevalence of type
2 diabetes in people following different types of vegetarian diets compared with that
in nonvegetarians...The 5-unit BMI difference between vegans and nonvegetarians indicates a
substantial potential of vegetarianism to protect against obesity. Increased
conformity to vegetarian diets protected against risk of type 2 diabetes after lifestyle
characteristics and BMI were taken into account. Pesco- and semi-vegetarian diets afforded
intermediate protection."
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Veganism, bone mineral density, and
body composition: a study in Buddhist nuns by Ho-Pham LT, Nguyen PL, Le TT, Doan TA,
Tran NT, Le TA, Nguyen TV in Osteoporos Int. 2009 Dec;20(12):2087-93.
"...(A)lthough vegans had lower dietary calcium and protein intakes than omnivores,
veganism did not have adverse effect on bone mineral density and did not alter body
composition....(A)lthough vegans have much lower intakes of dietary calcium and protein
than omnivores, veganism does not have adverse effect on bone mineral density and does not
alter body composition.
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A low-fat vegan diet and a
conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled,
74-wk clinical trial by Barnard ND, Cohen J, Jenkins DJ, Turner-McGrievy G, Gloede L,
Green A, Ferdowsian H in Am J Clin Nutr. 2009 May;89(5):1588S-1596S. "...We
compared the effects of a low-fat vegan diet and conventional diabetes diet
recommendations on glycemia, weight, and plasma lipids...Both diets were associated with
sustained reductions in weight and plasma lipid concentrations. In an analysis controlling
for medication changes, a low-fat vegan diet appeared to improve glycemia and plasma lipids
more than did conventional diabetes diet recommendations. Whether the observed differences
provide clinical benefit for the macro- or microvascular complications of diabetes remains
to be established..."
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Serum 25-hydroxyvitamin D status of
vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2 by
Chan J, Jaceldo-Siegl K, Fraser GE in Am J Clin Nutr. 2009 May;89(5):1686S-1692S.
"...We assessed serum 25-hydroxyvitamin D [s25(OH)D] concentrations and factors
affecting them in vegetarians, partial vegetarians, and nonvegetarians in a sample of
calibration study subjects...s25(OH)D concentrations were not associated with vegetarian
status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and
amount and intensity of sun exposure have greater influence on s25(OH)D than does
diet."
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Cancer incidence in vegetarians:
results from the European Prospective Investigation into Cancer and Nutrition
(EPIC-Oxford) by Key TJ, Appleby PN, Spencer EA, Travis RC, Roddam AW, Allen NE in
Am J Clin Nutr. 2009 May;89(5):1620S-1626S. "...This was a prospective study of
63,550 men and women recruited throughout the United Kingdom in the 1990s. Cancer
incidence was followed through nationwide cancer registries...The overall cancer
incidence rates of both the vegetarians and the nonvegetarians in this study are low
compared with national rates. Within the study, the incidence of all cancers combined was
lower among vegetarians than among meat eaters, but the incidence of colorectal cancer was
higher in vegetarians than in meat eaters."
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Mortality in British vegetarians:
results from the European Prospective Investigation into Cancer and Nutrition
(EPIC-Oxford) by Key TJ, Appleby PN, Spencer EA, Travis RC, Roddam AW, Allen NE in
Am J Clin Nutr. 2009 May;89(5):1613S-1619S. "...We present results on
mortality among vegetarians and nonvegetarians in the European Prospective
Investigation into Cancer and Nutrition (EPIC-Oxford)...The mortality of both the
vegetarians and the nonvegetarians in this study is low compared with national rates.
Within the study, mortality from circulatory diseases and all causes is not significantly
different between vegetarians and meat eaters, but the study is not large enough to exclude
small or moderate differences for specific causes of death..."
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Changes in nutrient intake and
dietary quality among participants with type 2 diabetes following a low-fat vegan diet or a
conventional diabetes diet for 22 weeks by Turner-McGrievy GM, Barnard ND, Cohen J,
Jenkins DJ, Gloede L, Green AA in J Am Diet Assoc. 2008 Oct;108(10):1636-45.
"...To assess the changes in nutrient intake and dietary quality among participants
following a low-fat vegan diet or the 2003 American Diabetes Association dietary
recommendations....Vegan diets increase intakes of carbohydrate, fiber, and several
micronutrients, in contrast with the American Diabetes Association recommended diet. The
vegan group improved its AHEI score whereas the American Diabetes Association recommended
diet group's AHEI score remained unchanged."
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The low-methionine content of vegan
diets may make methionine restriction feasible as a life extension strategy by McCarty
MF, Barroso-Aranda J, Contreras F by Med Hypotheses. 2009 Feb;72(2):125-8.
"Recent studies confirm that dietary methionine restriction increases both mean and
maximal lifespan in rats and mice, achieving "aging retardant"...(I)t may be more
feasible to achieve moderate methionine restriction, in light of the fact that vegan diets
tend to be relatively low in this amino acid. Plant proteins - especially those derived
from legumes or nuts - tend to be lower in methionine than animal proteins. Furthermore,
the total protein content of vegan diets, as a function of calorie content, tends to be
lower than that of omnivore diets, and plant protein has somewhat lower bioavailability
than animal protein..."
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Alteration of cardiovascular
autonomic functions by vegetarian diets in postmenopausal women is related to LDL
cholesterol levels by Fu CH, Yang CC, Lin CL, Kuo TB in Chin J Physiol. 2008 Apr
30;51(2):100-5. "This study was designed to test the hypothesis that alteration of
cardiovascular autonomic functions by vegetarian diets in healthy postmenopausal
women is related to lipid metabolism...The vegetarians had statistically significant
lowered blood pressure, total cholesterol, low-density lipoprotein (LDL) cholesterol,
triglyceride, and fasting glucose levels compared with the omnivores...Total power, LF and
HF of HRV, Brr(LF), and Brr(HF) were significantly and negatively correlated with
LDL-cholesterol concentrations...We concluded that the increases of cardiac vagal activity
and baroreflex sensitivity by vegetarian diets in postmenopausal women are inversely
related to LDL-cholesterol levels."
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The relative impact of a
vegetable-rich diet on key markers of health in a cohort of Australian adolescents by
Grant R, Bilgin A, Zeuschner C, Guy T, Pearce R, Hokin B, Ashton J. in Asia Pac J Clin
Nutr. 2008;17(1):107-15. "...We compared key physiological and biochemical markers
of health against responses to a modified, Schools Physical Activity and Nutrition Survey
(SPANS)...Adolescents consuming predominantly vegetarian foods showed significantly better
scores on markers of cardiovascular health, including, body mass index (BMI), waist
circumference, Cholesterol/High density lipoprotein ratio and low density lipoprotein.
Adolescents consuming nuts more than once per week, also showed lower scores for BMI and
serum glucose irrespective of their vegetarian status. Markers of general health including
haemoglobin and average height were not different between groups; however a lower serum
level of vitamin B12 was apparent in the vegetarian cohort. Surprisingly, exercise on its
own was not statistically associated with any of the risk factors tested suggesting that
diet may be the most significant factor in promoting health in this age group."
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Gluten-free vegan diet induces
decreased LDL and oxidized LDL levels and raised atheroprotective natural antibodies
against phosphorylcholine in patients with rheumatoid arthritis: a randomized study by
Elkan AC, Sj?berg B, Kolsrud B, Ringertz B, Hafstr?m I, Frosteg?rd J in Arthritis Res
Ther. 2008;10(2):R34. "...The purpose of this study was to investigate the effects
of vegan diet in patients with rheumatoid arthritis (RA) on blood lipids oxidized
low-density lipoprotein (oxLDL) and natural atheroprotective antibodies against
phosphorylcholine (anti-PCs)...A gluten-free vegan diet in RA induces changes that are
potentially atheroprotective and anti-inflammatory, including decreased LDL and oxLDL
levels and raised anti-PC IgM and IgA levels."
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A very-low-fat vegan diet increases
intake of protective dietary factors and decreases intake of pathogenic dietary factors
by Dewell A, Weidner G, Sumner MD, Chi CS, Ornish D in J Am Diet Assoc. 2008
Feb;108(2):347-56. "...This study examined protective (eg, antioxidant vitamins,
carotenoids, and fiber) and pathogenic (eg, saturated fatty acids and cholesterol) dietary
factors in a very-low-fat vegan diet...These results suggest that a very-low-fat vegan diet
can be useful in increasing intake of protective nutrients and phytochemicals and
minimizing intake of dietary factors implicated in several chronic diseases."
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Cardiovascular risk in vegetarians
and omnivores: a comparative study by Teixeira Rde, Molina Mdel, Zandonade E, Mill JG
in Arq Bras Cardiol. 2007 Oct;89(4):237-44 "...To describe and analyze the
cardiovascular risk (CVR) in vegetarians and omnivores residing in Greater Vit?ria,
State of Esp?rito Santo, Brazil, in the age range from 35 to 64...Unbalanced omnivorous
diet with excess animal protein and fat may be implicated, to a great extent, in the
development of noncommunicable diseases and conditions, especially in the CVR."
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From beans to berries and beyond:
teamwork between plant chemicals for protection of optimal human health by Lila MA in
Ann N Y Acad Sci. 2007 Oct;1114:372-80. "...In order to investigate the
strength of natural chemical cooperation in highly-pigmented, flavonoid-rich functional
foods, our lab has relied on analysis of both whole fruits, and continuous, reliable plant
cell culture production systems which accumulate anthocyanins and proanthocyanidins in high
concentrations. Successive rounds of relatively gentle, rapid, and large-volume
fractionations are linked to bioassay of complex to simple mixtures and semi-purified
compounds. By means of this strategy, additive interactions or synergies between related
compounds in health maintenance can be sorted out. Interestingly, phytochemical
interactions between the same classes of compounds intensify the efficacy of flavonoid-rich
fruits against multiple, not necessarily discrete, human disease conditions including CVD,
cancer, metabolic syndrome, and others."
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A two-year randomized weight loss
trial comparing a vegan diet to a more moderate low-fat diet by Turner-McGrievy GM,
Barnard ND, Scialli AR in Obesity (Silver Spring). 2007 Sep;15(9):2276-81.
"...The objective was to assess the effect of a low-fat, vegan diet compared with the
National Cholesterol Education Program (NCEP) diet on weight loss maintenance at 1
and 2 years...A vegan diet was associated with significantly greater weight loss than the
NCEP diet at 1 and 2 years. Both group support and meeting attendance were associated with
significant weight loss at follow-up."